The present invention relates generally to the field of discontinuity sensors, and, in particular, to the art of detecting the location of a discontinuity in a workpiece.
Discontinuity sensors (also referred to in this document as probes) have been well known for some time. One known discontinuity sensor is disclosed in U.S. Pat. No. 5,168,638 to Barton, the disclosure of which is hereby incorporated herein by reference. A known discontinuity sensor is illustrated in FIGS. 1A and 1B. As illustrated in FIGS. 1A and 1B, typical prior art discontinuity sensors include a shaft 222, a handle 224, a pair of measuring slides 266, pair of offset slide assemblies 268, an end unit 270, a spacer 274, an activator 272, and a pair of position indicators 228. The position indicators 228 may be held in place by a clamp 210 fastened into place by screws located in radial bores 236. Generally, movement of the end unit at the distal end of the shaft causes movement of one or more of the slides, and that movement is translated to the position indicators for feedback to the user.
Unfortunately, known discontinuity sensors suffer from at least two primary drawbacks. First, if the length of the sensor is to be varied, then at least some of the parts must likewise be varied in order to accommodate the change in length of the sensor. Second, because some of the operating components of the sensor are disposed in the handle while others are disposed in the shaft, the accuracy of a sensor of this type may be compromised by slight movements of the handle relative to the shaft. These slight movements may be caused by temperature variations and the like. Thus, a discontinuity sensor is needed which is comprised predominantly of components which are capable of use in a sensor of any length, and which includes all operating components mounted on or in the shaft and separate from the handle.
It is therefore a feature and advantage of the present invention to provide a probe capable of locating the location of a feature in a workpiece such as a hole, slot, post, or other artifact. The probe may use shafts of different lengths.
It is another feature and advantage of the present invention to provide a probe that has a handle, a wire strain assembly and other features facilitating use.
The features mentioned above and other features and advantages are achieved through the use of a novel discontinuity sensor as herein disclosed. In accordance with one embodiment of the present invention, a probe having a shaft attached to a handle for locating a discontinuity in relation to a coordinate system is provided. The probe includes: a handle; a shaft attached to the handle; an end unit attached to an end of the shaft opposite an end of the shaft that the handle is attached, the end unit configured to contact a surface associated with the discontinuity and move in relation to the coordinate system to align the end unit to an axis associated with the discontinuity; and at least one position sensor located substantially within the shaft configured to sense the position of the end unit in relation to the coordinate system, wherein the shaft includes a plurality of bores and the sensor is located within at least one of the bores.
In accordance with another embodiment of the present invention, a probe for locating a feature of a workpiece in relation to a coordinate system is provided. The probe includes: a handle; a shaft attached to the handle; an end unit attached to an end of the shaft opposite an end of the shaft that the handle is attached, the end unit configured to sense a surface associated with the discontinuity to allow alignment to an axis associated with the discontinuity; and a sensing means located substantially within the shaft configured to sense the position of the end unit in relation to the coordinate system.
In accordance with another embodiment of the present invention, a method of using a probe to locate a feature in a workpiece is provided. The method includes: orienting the probe with a known coordinate system by using an alignment flange of the probe; inserting a conical end unit portion of a probe into the feature; permitting the end unit to slide radially as the end unit is inserted into the feature to cause the end unit portion of the probe to rest against a surface defining at least part of the feature; tracking the sliding movement of the end unit with sliding members; biasing the end unit to a predetermined position with biasing members; sensing the siding movement of the sliding members; and generating a signal related to an amount of distance the end unit has moved with respect to the coordinate system.
There has thus been outlined, rather broadly, some features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.